EVEN AS the Legislature deliberates over how to fund the state’s cash-strapped transportation systems, it’s not too soon for the MBTA to begin thinking about future expansions — especially the kind that promise to serve more customers at a relatively modest investment. At least on paper, the T’s proposal to extend Silver Line service to Chelsea fits that description. Chelsea is the kind of dense but often neglected urban community that more predictable, effective public transit has the potential to invigorate.

What’s less clear is whether an extension of the Silver Line, the T’s controversial “bus rapid transit” service, will be adequate to provoke such a renaissance. As T officials contemplate a northward extension of the line past Logan Airport, the agency should look for ways to improve the speed and usefulness of the Silver Line more generally.

The line was designed in part as a cheaper substitute for the elevated Orange Line along Washington Street, and it follows a fixed route as the T’s four rail lines do. Yet the Silver Line uses buses with rubber tires, and most of its “stations” are essentially bus stops with more conspicuous signage. At bus rapid transit systems in some other cities, passengers pay to enter special waiting platforms, and once the bus arrives they can board it quickly; on the Silver Line, passengers pay as they get on the bus, which can slow the system down significantly.

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Meanwhile, by promoting the Silver Line as a subway-lite the MBTA has set expectations that the service can’t satisfy. Unlike subways, whose advantages over automobiles are most pronounced at rush hour, Silver Line buses are largely at the mercy of street traffic. Buses that cruise along Washington Street through the South End, where traffic is relatively light, slow down markedly once they cross into Chinatown and the Downtown Crossing area.

Still, the Silver Line can do more to take advantage of the benefits that buses offer. In Bogota, Colombia, a bus rapid transit system known as Transmilenio allows buses to save time by skipping several stops at a time. While the scheduling is complicated, the upshot is that during peak periods passengers get faster service. Especially if Silver Line service to Chelsea ends up being routed through well-used urban streets, some ability to skip stops and send out express buses could make the service faster.

Despite its flaws, the Silver Line fills an important need, and therefore has greater ridership than most MBTA bus routes. By the T’s own calculations, some Silver Line routes even make a profit — a rarity in public transportation. When the Silver Line was originally planned, many standard features of bus rapid transit systems were considered and dismissed for reasons of money and of logistics. It’s exceedingly unlikely every current Silver Line stop can be retrofitted with waiting platforms. But at the least, the T should use what other transit agencies elsewhere have learned to improve its plans for Chelsea.